Owing to the steadily increasing output of mobile, electrically operated devices, the requirements made of the batteries employed, which are also sometimes referred to as accumulators, are also on the rise. The currents, which in some cases are high during the charging and discharging of the batteries, cause the batteries to heat up considerably. This is why batteries according to the state of the art are often cooled during operation.
For instance, European patent specification EP 1 178 557 B1 discloses a cordless electric power tool having a housing, a removable battery and a battery charger for charging the battery. The battery has a housing with one or more cells and a ventilation system that allows air to flow around the cells. The battery charger has a fan that generates the above-mentioned air flow. Finally, the electric tool comprises a heat pump for cooling or warming up the battery cells.
Furthermore, European patent application EP 1 381 134 A1 discloses a charging station for a rechargeable battery that can be electrically and structurally connected to the station. This charging station comprises an electric and structural contact interface for the battery as well as charging electronics in a charger housing. An air blower that serves to generate an air stream through two ventilation openings is arranged in the charger housing, whereby a ventilation opening of the contact interface is structurally associated with the battery and the charging electronics are arranged in the air stream so that their heat is dissipated. In a first method step during the cooling process, a volume of air at a cooling temperature is moved past the battery and, in a second method step, the volume of air at an intermediate temperature passes through the charger housing containing the charging electronics.
Finally, European patent specification EP 1 419 723 B1 discloses a vacuum cleaner that has several battery docks that can be used in the cited vacuum cleaner as well as in other handheld electric tools. The vacuum cleaner can be operated connected to the mains or else it can be autonomously powered by the batteries.